1. Field of the Invention
The present invention relates to a separation type hole saw in which a hole saw can be, freely attached and detached and the hole saw can be easily replaced in a one-touch manner.
2. Description of the Related Art
Conventionally, the hole saw has had various kinds of drilling holes and has been required to be always provided with various kinds of hole saw mounting metal fittings being different in an effective length of a blade portion, a length of a center pin, a shape of a shank and the like. Accordingly, there has been a problem that a lot of time and labor is required for treating the hole saw and the treatment is troublesome, and the like. Therefore, a separation type hole saw tends to be increased in comparison with an integration type hole saw.
FIG. 1 shows a schematic view of a conventional separation type hole saw. In the drawing, a separation hole saw 1 is structured such that a hole saw 3 is integrally fixed to a mounting metal fitting 2 and is connected to a drilling portion of a working machine (not shown) by a detachable shank 5 and a screw portion 4. Further, a center pin (or a center guide drill or the like) 6 used as a center guide at a time of drilling is provided in the shank 5 and is fixed by a fastening screw 7. In this case, a spring 8 is inserted into a center pin 6, and is structured such that one end forms a stationary end being fixed to the mounting metal fitting 2 and another end forms a free end so as to remove blanks (piercing refuses) during the drilling.
FIG. 2 shows an explanatory view of a using method of the separation type hole saw shown in FIG. 1. In the drawing, the separation type hole saw is constituted by two kinds of large and small hole saws, 3A and 3B, mounting metal fitting 2A and 2B, shanks 5A and 5B, center guide drills 6A and 6B and an intermediate connection metal fitting 9. As mentioned above, in the case that the sizes are different, the intermediate connection metal fitting 9 is frequently required. In this case, hexagonal fitting portions a and b fitting to each other are provided among the mounting metal fittings 2A and 2B, the shanks 5A and 5B and the intermediate connection metal fitting 9, and are respectively fixed by a fastening screw 11, so as to be prevented from falling off.
However, since a hexagonal wrench for fastening and loosening the fastening screw 7 is required for a replacing operation of the center pin (or the center guide drill or the like) 6, and a tool such as a spanner or the like is required for a replacing operation of the hole saw 3, there is a problem that a treatment thereof is troublesome and a working operability is reduced.
In order to solve the problems mentioned above, an object of the present invention is to provide a separation type hole saw in which a hole saw is replaced in a one-touch manner, is detachable, is easily treated and has an improved operation efficiency.
A first aspect of the present invention provides a separation type hole saw comprising: a hole saw (3) a hole saw mounting metal fitting (2), in which one end of the hole saw mounting metal fitting (2) is integrally mounted to the hole saw (3), and a polygonal fitting convex portion (2a) is formed in another end of the hole saw mounting metal fitting (2); a shank (5), in which a polygonal fitting recess portion (5a) is formed in one end of the shank (5), the fitting convex portion (2a) of the hole saw mounting metal fitting (2) is inserted to the fitting recess portion (5a), another end of the shank (5) is attached to a rotational shaft portion of a working machine, a hole portion (12) extending through the fitting recess portion (5a) from an outer peripheral surface of the shank (5) is provided, and an annular groove (15) is formed in an outer periphery at a position of the hole portion (12) of the shank (5); a spherical body (13) inserted to the hole portion (12); an annular spring (14) inserted to the annular groove (15), the annular spring (14) urging the spherical body (13) so that the spherical body (13) presses the fitting convex portion (2a) of the hole saw mounting metal fitting (2), thereby preventing the fitting recess portion (5a) of the shank (5) from being taken out from the fitting convex portion (2a) of the hole saw mounting metal fitting (2) due to the pressing operation of the spherical body (13); a center pin (6) inserted to a center portion of the shank (5) and guiding the hole saw (3) at a time of drilling a material, in which a guide groove (19) is formed in an outer periphery of an end portion of the center pin (6) inserted to the shank (5); and a fitting member (22) provided in the shank (5), the fitting member (22) being fitted to and detached from the guide groove (19), whereby the center pin (6) is fixed to the shank (5) and is freely detached from the shank (5).
A second aspect of the present invention, as it depends from the first aspect, provides a separation type hole saw, in which the guide groove (19) is an inclined groove structured such that a depth of the groove is increased along a rotational direction of the center pin (6).
According to the separation type hole saw of the first and second aspects mentioned above, since a replacing operation of the hole saw can be simply performed with one action and a treatment thereof is easy, an operation efficiency can be improved.
A third aspect of the present invention provides a separation type hole saw comprising: a hole saw (103); a hole saw mounting metal fitting (114), in which one end of the hole saw mounting metal fitting (114) is integrally mounted to the hole saw (103), a fitting convex portion (114a) is formed in another end of the hole saw mounting metal fitting (114), and a first annular groove (118) is formed in an outer periphery of the fitting convex portion (114a); a shank (115), in which a polygonal fitting recess portion (115a) is formed in one end of the shank (115), the fitting convex portion (114a) of the hole saw mounting metal fitting (114) is inserted to the fitting recess portion (115a), another end of the shank (115) is attached to a rotational shaft portion of a working machine, a first hole portion (116) extending through the fitting recess portion (115a) from an outer. peripheral surface of the shank (115) is provided, a second annular groove (121) is formed in an outer periphery at a position of the first hole portion (116) of the shank (115), a center pin insertion hole (127) if formed in the shank (115), a second hole portion (123) extending through the center pin insertion hole (127) from an outer peripheral surface is further formed in the shank (115), and a third annular groove (125) is formed in an outer periphery at a position of the second hole portion (123) of the shank (115); a first spherical body (117) inserted to the first hole portion (116); a first annular spring (120) inserted to the second annular groove (121), the first annular spring (120) urging the first spherical body (117):so that the first spherical body (117) presses the fitting convex portion (114a) of the hole saw mounting metal fitting (114), thereby preventing the fitting recess portion (115a) of the shank (115) from being taken out from the fitting convex portion (114a) of the hole saw mounting metal fitting (114) due to the pressing operation of the first spherical body (117); a center pin (6) inserted to a center portion of the shank (115):and guiding the hole saw (103) at a time of drilling a material, in which a circular arc groove (126) is formed in an outer peripheral surface of an end portion of the center pin (6) inserted to the shank (115); a second spherical body (124) inserted to the second hole portion (123); a second annular spring (122) inserted to the third annular groove (125), the second annular spring (122) urging the second spherical body (124) so that the second spherical body (124) presses the circular arc groove (126) of the center pin (6), thereby preventing the center pin (6) from being taken out from the center pin insertion hole (127) due to the pressing operation of the second spherical body (124); and an outer peripheral ring (113) provided in an outer periphery of the shank (115). in which the first annular spring (120) and the second annular spring (122) rotate at a desired rotational angle and a pressing force applied to the first spherical body (117) and the second spherical body (124) by the first annular spring (120) and the second annular spring (122) is changed when the outer peripheral ring (113) is rotated around a shaft of the shank (115), whereby a locking and canceling operation of the center pin (6) with respect to the center pin insertion hole (127) and a locking and canceling operation between the fitting recess portion (115a) of the shank (115) and the fitting convex portion (114a) of the hole saw mounting metal fitting (114) are simultaneously performed.
A fourth aspect of the present invention, provides a separation type hole saw according to the third aspect, wherein a third hole portion (141) extending through the center pin insertion hole (127) is formed in the outer peripheral surface of the shank (115), a third spherical body (143) is inserted to the third hole portion (141), the third spherical body (143) presses the annular arch groove (126) of the center pin (6) so as to prevent the center pin (6) from being taken out from the center pin insertion hole (127), and the locking and canceling operation of the center pin (6) with respect to the center pin insertion hole (127) is performed by rotating the outer peripheral ring (113) at a desired rotational angle.
A fifth aspect of the present invention provides a separation type hole saw according to the third or fourth aspect, wherein a guide groove (129) is formed in an inner surface of the outer peripheral ring (113), a fourth spherical body (131) is inserted between the guide groove (129) and the shank (115), and the guide groove (129) is formed such that a rotational angle of the outer peripheral ring (113) is kept 60 degrees.
A sixth aspect of the present invention provides a separation type hole saw according to the third aspect, the fourth aspect or the fifth aspect, wherein the first hole portion (116) is uniformly separated into three sections in a direction of extending through the fitting recess portion (115a) from the outer peripheral surface of the shank (115), and three first spherical bodies (117) are respectively inserted to the three first hole portions (116).
According to the separation type hole saws of the third to sixth aspects mentioned above, since a replacing operation of the hole saw can be simply performed with one action and a treatment thereof is easy, an operation efficiency can be improved. Further, a concentricity of the members on the basis of the respective elements, that is, an accuracy at which the centers of the elements coincide with each other can be improved and a quality can be improved.